Improvement in insertible saw-teeth



J. L. BERRY. In-sertible Saw-Teeth No. 207,003.- Patehted Aug. 13,1878;

' #2566826: r v Z z r ERS. PHo'ro-umoampnen, WASHINGTON. D C. i

UNITED S ATES-PATENT Onnrcn JAMES .L. BERRY, OF SAGINAV, lVIIGHIGAN.

IMPROVEMENT .lN INSERTiBLE SAW-TEETH.

Specification forming part of Letters Patent N0.-207,003, dated August13, 1878; application filed July 22, 1878.

To all whom it may concern Be it known that I, JAMES L. BERRY, of thecity of Saginaw, in the State of Michigan, have invented an Improvementin Insertible Saw-Teeth, whereby they may be readily removed andreplaced in such a manner as to prevent all injurious strain upon thesawblade, and the invention consists in the employment of aretaining-yoke or locking-plate of peculiar construction, and a groovedcam or circular key that serves to hold the lockingplate in place in thesaw-plate, the cam occupying a circular hole or opening, which is formedmainly in the locking'plate and the remainder in the saw-plate, togetherwith certain peculiarities of form in the tooth, and in the recesses inthe saw and locking-plate into which it is inserted, all as will behereinafter fully described, and then specifically pointed out in theclaims.

In the drawing, Figure 1 is a side view of a piece of a saw-plate with atooth inserted and secured therein. Fig. 2 is an edge view of thetooth-locking plate and circular cam, lookin g in the direction of thearrow in Fig. 1. Fig.

3 is a side view of the saw-plate with the locking-plate inserted andsaw-tooth and cam removed. Fig. 41 shows a detailed view of the circularcam or wedge.

In the drawings, A represents a part of the blade of a circular saw; B,the yoke or looking-plate for holding the tooth (J. The tooth isexpanded or swaged at its point so that it will cut a kerf wide enoughto clear the sawplate, thus preventing friction and the consequentheating of the plate.

The back side, a, of the tooth O, which may be straight, or nearly so,is furnished with a triangular or V-shaped groove, which extends aroundits lower end and up its front side as far as the top edge of thelocking-plate B, thus giving it a firm seat upon the triangulartongue 1) formed upon the edge of the recess in the saw-plate, and alsoin the recess formed in the locking-plate.

The front edge of the tooth presents a straight, or nearly straight,outline, and is provided in its triangular groove with a convex lug orhook, d, made tofit the recess 0 formed in the V-shaped edge of thelockin plate, to receive it, so as to hold the tooth securely inposition and prevent it from becoming loose when in use.

The front or cutting portion of the tooth'is made concave orgouge-shaped, for the purpose of cutting more easily, smoothly, and withgreater facility, at the same time requiring less power to operate thesaw.

The locking-plate or yoke B is adapted to fit closely into the recess oropening made in the saw-blade to receive it. The bottom of this recess,and also its sides, are straight, as shown, and provided with V-shapededges or triangular tongues, which fit into the triangular or V-shapedgrooves formed upon the sides and end of the locking-plate B. Anabutment or shoulder, c, is formed in one side of the locking-plate toreceive the tooth and to serve as a support for the tooth against thethrust of the cut.

The cam D (shown in Fig. 4) is provided with a V-shaped groove adaptedto fith the V-shaped tongue formed upon the edges of the opening made toreceive it. This cam fits and turns in a circularcavity formed mostly in-the locking-plate B and partly in the sawplate A. The periphery of thecam is circular at the outerf'sides'about two'thirds around, more orless, and, upon one side is flat with a grooved edge, which, when thecam is in position to allow the insertion or removal of thelocking-plate and tooth, is straight with the side of the locking-plateB. After the lockingplate and tooth are inserted, and the cam given aquarter turn or more, the yoke and tooth are firmly and securelyfastened in place. A keyhole, I, is formed in cam D to receive the endof a key, by which the cam is turned when it becomes necessary towithdraw the lockingplate and tooth, or to secure the same again inposition. The top part of the locking-plate is curved to correspond tothe throat of the tooth.

Hitherto the greatest objection to inserted teeth has been the tendencythey have to strain the saw' when they are held in placeby wedges orrivets,which must, if tight enoughto retain the tooth, exert a greatexpansive force upon the periphery of the saw-blade, causing it to beaffected by such changes in temperature as are likely to occur at anytime when the saw is in use, causing the saw to buckle. Thus, by addingto the friction, the saw becomes liable to deflect from its directcourse through the lumber. In my saw these diificulties are overcome,and it should be understood that although the locking-plate, tooth, andcam fit accurately to their places, and with sufficient tightness toprevent displacement, no such force is required to introduce them as canaffect the integrity of the blade.

I claim as my invention- The combination of locking -pla'te B, providedwith abutment c and recess 0 tooth 0, having lug orhook 01, adapted tofit the recess 0, with the circular grooved cam D and saw-plate A,substantially in the manner and for the purpose specified.

. JAMES L. BERRY.

In presence of- 7M. A. CLARK, F. BUsoH.

